Event Details

Optical quantum networks may have many applications in secure quantum communication, computation and metrology. Quantum networks require nodes which efficiently interface photons to registers of long-lived quantum memories which can be controlled with high fidelity. I will present a platform based on a silicon-vacancy-color-center (SiV) coupled to a nearby nuclear spin and embedded in a diamond nanocavity, which fulfills all of these requirements. The high cooperativity SiV-cavity system (C = 38) provides a deterministic interface between itinerant photons and the electron spin, with a coherence time exceeding 1 ms. Employing coherent microwave control, we generate high-fidelity spin-photon entanglement and implement heralded photon storage in the nanophotonic register. Finally, we demonstrate universal control over a cavity-coupled two-qubit register consisting of a SiV and a proximal 13C spin with coherence time approaching one second. These results pave the way for preparing of large 2D photonic cluster states and demonstration of first-generation quantum repeaters.